TACT Trial Shows High-Dose Oral Vitamins No Help Post-MI

Mar 10, 2013

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The initial results of TACT, the Trial to Assess Chelation Therapy, released during an ACC.13 Late Breaking Clinical Trial session on March 10 suggest that while high-dose oral supplements have an additive effect with intravenous chelation, they do not have a significant impact on their own.

The results showed that EDTA chelation can reduce a composite cardiovascular endpoint in patients following an MI; however, the initial findings were unclear because many practitioners of chelation also use high doses of anti-oxidant vitamins and minerals in conjunction with chelation. Oral vitamins and minerals were an admitted confounder when the initial results were announced in 2012.

"The primary endpoint, time to the first of death, MI, stroke, coronary revascularization or hospitalization for angina, was not statistically significant for high-dose oral vitamins and minerals," said Gervasio Lamas, MD, professor of clinical medicine, Mount Sinai Medical Center, Miami Beach, FL. "The results of this study do not support the use of high-dose vitamins and minerals as an adjunct to optimal evidence-based medical therapy for patients with prior myocardial infarction."

A total of 1,708 post-MI patients were randomized to four groups: active oral vitamins plus active IV chelation; placebo vitamins and active chelation; active vitamins and placebo chelation; or placebo vitamins and placebo chelation. The vitamin regimen included three caplets twice daily for the duration of the study.

The primary endpoint for EDTA chelation, presented in 2012, showed a hazard ratio of 0.82 for chelation (p=0.035) for the primary endpoint after five years of follow-up. Adding vitamins to chelation lowered the hazard ratio to 0.74 (p=0.016). But vitamins alone showed a hazard ratio of 0.89 (p=0.212), a nonsignificant difference compared to placebo. A subanalysis showed that vitamins alone did provide an advantage for patients who were on statins at baseline with a hazard ratio of 0.62 (p=0.01), but not in any other subgroups.

"These findings should stimulate further research," Lamas added, "but are not, by themselves, sufficient to recommend the routine use of chelation therapy and high-dose vitamins in post-MI patients. We have moved this treatment from the realm of alternative medicine, but to move it into the mainstream would be premature since it introduces mechanisms we do not understand. That understanding is where we should be heading," he noted.